[FEATURE] [needs-docs] Point Displacement label distance factor

henrik · nyalldawson · commit 6fb06738ecfa · 2019-03-26T18:17:12.000+10:00
Adds label distance factor spinbox to Point Displacement symbology window. Calculates label distance based on the current symbology diagonal instead of a general maximum diagonal. Replaces the hard coded distance "symbolDiagonal/2.0" with "symbolDiagonal*mLabelDistanceFactor", where mLabelDistanceFactor is set to the spinbox value. It's an old feature request (Point displacement labels adjustable offsets "https://issues.qgis.org/issues/5945").
diff --git a/python/core/auto_generated/symbology/qgspointdisplacementrenderer.sip.in b/python/core/auto_generated/symbology/qgspointdisplacementrenderer.sip.in
@@ -104,6 +104,22 @@ Sets a factor for increasing the ring size of displacement groups.
 Returns the factor for increasing the ring size of displacement groups.
 
 .. seealso:: :py:func:`setCircleRadiusAddition`
+%End
+
+    void setLabelDistanceFactor( double factor );
+%Docstring
+Sets a factor for increasing the label distances from the symbol.
+
+:param factor: addition factor
+
+.. seealso:: :py:func:`labelDistanceFactor`
+%End
+
+    double labelDistanceFactor() const;
+%Docstring
+Returns the factor for label distance from the symbol.
+
+.. seealso:: :py:func:`setLabelDistanceFactor`
 %End
 
     Placement placement() const;
diff --git a/src/core/symbology/qgspointdisplacementrenderer.cpp b/src/core/symbology/qgspointdisplacementrenderer.cpp
@@ -43,6 +43,7 @@ QgsPointDisplacementRenderer *QgsPointDisplacementRenderer::clone() const
   r->setLabelColor( mLabelColor );
   r->setPlacement( mPlacement );
   r->setCircleRadiusAddition( mCircleRadiusAddition );
+  r->setLabelDistanceFactor( mLabelDistanceFactor );
   r->setMinimumLabelScale( mMinLabelScale );
   r->setTolerance( mTolerance );
   r->setToleranceUnit( mToleranceUnit );
@@ -60,12 +61,21 @@ void QgsPointDisplacementRenderer::drawGroup( QPointF centerPoint, QgsRenderCont
 
   //calculate max diagonal size from all symbols in group
   double diagonal = 0;
+  QList<double> diagonals;
+  double currentDiagonal;
 
   for ( const GroupedFeature &feature : group )
   {
     if ( QgsMarkerSymbol *symbol = feature.symbol() )
     {
-      diagonal = std::max( diagonal, M_SQRT2 * symbol->size( context ) );
+      currentDiagonal = M_SQRT2 * symbol->size( context );
+      diagonals.append( currentDiagonal );
+      diagonal = std::max( diagonal, currentDiagonal );
+
+    }
+    else
+    {
+      diagonals.append( 0.0 );
     }
   }
 
@@ -77,7 +87,7 @@ void QgsPointDisplacementRenderer::drawGroup( QPointF centerPoint, QgsRenderCont
   double gridRadius = -1.0;
   int gridSize = -1;
 
-  calculateSymbolAndLabelPositions( symbolContext, centerPoint, group.size(), diagonal, symbolPositions, labelPositions, circleRadius, gridRadius, gridSize );
+  calculateSymbolAndLabelPositions( symbolContext, centerPoint, group.size(), diagonal, symbolPositions, labelPositions, circleRadius, gridRadius, gridSize, diagonals );
 
   //only draw circle/grid if there's a pen present - otherwise skip drawing transparent grids
   if ( mCircleColor.isValid() && mCircleColor.alpha() > 0 )
@@ -149,6 +159,7 @@ QgsFeatureRenderer *QgsPointDisplacementRenderer::create( QDomElement &symbology
   r->setCircleColor( QgsSymbolLayerUtils::decodeColor( symbologyElem.attribute( QStringLiteral( "circleColor" ), QString() ) ) );
   r->setLabelColor( QgsSymbolLayerUtils::decodeColor( symbologyElem.attribute( QStringLiteral( "labelColor" ), QString() ) ) );
   r->setCircleRadiusAddition( symbologyElem.attribute( QStringLiteral( "circleRadiusAddition" ), QStringLiteral( "0.0" ) ).toDouble() );
+  r->setLabelDistanceFactor( symbologyElem.attribute( QStringLiteral( "labelDistanceFactor" ), QStringLiteral( "0.5" ) ).toDouble() );
   r->setMinimumLabelScale( symbologyElem.attribute( QStringLiteral( "maxLabelScaleDenominator" ), QStringLiteral( "-1" ) ).toDouble() );
   r->setTolerance( symbologyElem.attribute( QStringLiteral( "tolerance" ), QStringLiteral( "0.00001" ) ).toDouble() );
   r->setToleranceUnit( QgsUnitTypes::decodeRenderUnit( symbologyElem.attribute( QStringLiteral( "toleranceUnit" ), QStringLiteral( "MapUnit" ) ) ) );
@@ -186,6 +197,7 @@ QDomElement QgsPointDisplacementRenderer::save( QDomDocument &doc, const QgsRead
   rendererElement.setAttribute( QStringLiteral( "circleColor" ), QgsSymbolLayerUtils::encodeColor( mCircleColor ) );
   rendererElement.setAttribute( QStringLiteral( "labelColor" ), QgsSymbolLayerUtils::encodeColor( mLabelColor ) );
   rendererElement.setAttribute( QStringLiteral( "circleRadiusAddition" ), QString::number( mCircleRadiusAddition ) );
+  rendererElement.setAttribute( QStringLiteral( "labelDistanceFactor" ), QString::number( mLabelDistanceFactor ) );
   rendererElement.setAttribute( QStringLiteral( "placement" ), static_cast< int >( mPlacement ) );
   rendererElement.setAttribute( QStringLiteral( "maxLabelScaleDenominator" ), QString::number( mMinLabelScale ) );
   rendererElement.setAttribute( QStringLiteral( "tolerance" ), QString::number( mTolerance ) );
@@ -232,7 +244,7 @@ void QgsPointDisplacementRenderer::setCenterSymbol( QgsMarkerSymbol *symbol )
 
 void QgsPointDisplacementRenderer::calculateSymbolAndLabelPositions( QgsSymbolRenderContext &symbolContext, QPointF centerPoint, int nPosition,
     double symbolDiagonal, QList<QPointF> &symbolPositions, QList<QPointF> &labelShifts, double &circleRadius, double &gridRadius,
-    int &gridSize ) const
+    int &gridSize, QList<double> &diagonals ) const
 {
   symbolPositions.clear();
   labelShifts.clear();
@@ -243,8 +255,9 @@ void QgsPointDisplacementRenderer::calculateSymbolAndLabelPositions( QgsSymbolRe
   }
   else if ( nPosition == 1 ) //If there is only one feature, draw it exactly at the center position
   {
+    double side = sqrt( pow( symbolDiagonal, 2 ) / 2.0 );
     symbolPositions.append( centerPoint );
-    labelShifts.append( QPointF( symbolDiagonal / 2.0, -symbolDiagonal / 2.0 ) );
+    labelShifts.append( QPointF( side * mLabelDistanceFactor, -side * mLabelDistanceFactor ) );
     return;
   }
 
@@ -259,16 +272,19 @@ void QgsPointDisplacementRenderer::calculateSymbolAndLabelPositions( QgsSymbolRe
 
       double fullPerimeter = 2 * M_PI;
       double angleStep = fullPerimeter / nPosition;
-      for ( double currentAngle = 0.0; currentAngle < fullPerimeter; currentAngle += angleStep )
+
+      int featureIndex;
+      double currentAngle;
+      for ( currentAngle = 0.0, featureIndex = 0; currentAngle < fullPerimeter; currentAngle += angleStep, featureIndex++ )
       {
         double sinusCurrentAngle = std::sin( currentAngle );
         double cosinusCurrentAngle = std::cos( currentAngle );
         QPointF positionShift( radius * sinusCurrentAngle, radius * cosinusCurrentAngle );
-        QPointF labelShift( ( radius + symbolDiagonal / 2 ) * sinusCurrentAngle, ( radius + symbolDiagonal / 2 ) * cosinusCurrentAngle );
+
+        QPointF labelShift( ( radius + diagonals[featureIndex] * mLabelDistanceFactor ) * sinusCurrentAngle, ( radius + diagonals[featureIndex] * mLabelDistanceFactor ) * cosinusCurrentAngle );
         symbolPositions.append( centerPoint + positionShift );
         labelShifts.append( labelShift );
       }
-
       circleRadius = radius;
       break;
     }
@@ -279,6 +295,7 @@ void QgsPointDisplacementRenderer::calculateSymbolAndLabelPositions( QgsSymbolRe
       int pointsRemaining = nPosition;
       int ringNumber = 1;
       double firstRingRadius = centerDiagonal / 2.0 + symbolDiagonal / 2.0;
+      int featureIndex = 0;
       while ( pointsRemaining > 0 )
       {
         double radiusCurrentRing = std::max( firstRingRadius + ( ringNumber - 1 ) * symbolDiagonal + ringNumber * circleAdditionPainterUnits, 0.0 );
@@ -292,10 +309,11 @@ void QgsPointDisplacementRenderer::calculateSymbolAndLabelPositions( QgsSymbolRe
           double sinusCurrentAngle = std::sin( currentAngle );
           double cosinusCurrentAngle = std::cos( currentAngle );
           QPointF positionShift( radiusCurrentRing * sinusCurrentAngle, radiusCurrentRing * cosinusCurrentAngle );
-          QPointF labelShift( ( radiusCurrentRing + symbolDiagonal / 2 ) * sinusCurrentAngle, ( radiusCurrentRing + symbolDiagonal / 2 ) * cosinusCurrentAngle );
+          QPointF labelShift( ( radiusCurrentRing + diagonals[featureIndex] * mLabelDistanceFactor ) * sinusCurrentAngle, ( radiusCurrentRing + diagonals[featureIndex] * mLabelDistanceFactor ) * cosinusCurrentAngle );
           symbolPositions.append( centerPoint + positionShift );
           labelShifts.append( labelShift );
           currentAngle += angleStep;
+          featureIndex++;
         }
 
         pointsRemaining -= actualPointsCurrentRing;
@@ -315,15 +333,17 @@ void QgsPointDisplacementRenderer::calculateSymbolAndLabelPositions( QgsSymbolRe
       double userPointRadius =  originalPointRadius + circleAdditionPainterUnits;
 
       int yIndex = 0;
+      int featureIndex = 0;
       while ( pointsRemaining > 0 )
       {
         for ( int xIndex = 0; xIndex < gridSize && pointsRemaining > 0; ++xIndex )
         {
           QPointF positionShift( userPointRadius * xIndex, userPointRadius * yIndex );
-          QPointF labelShift( ( userPointRadius + symbolDiagonal / 2 ) * xIndex, ( userPointRadius + symbolDiagonal / 2 ) * yIndex );
+          QPointF labelShift( ( userPointRadius + diagonals[featureIndex] * mLabelDistanceFactor ) * xIndex, ( userPointRadius + diagonals[featureIndex] * mLabelDistanceFactor ) * yIndex );
           symbolPositions.append( centerPoint + positionShift );
           labelShifts.append( labelShift );
           pointsRemaining--;
+          featureIndex++;
         }
         yIndex++;
       }
diff --git a/src/core/symbology/qgspointdisplacementrenderer.h b/src/core/symbology/qgspointdisplacementrenderer.h
@@ -99,6 +99,19 @@ class CORE_EXPORT QgsPointDisplacementRenderer: public QgsPointDistanceRenderer
      */
     double circleRadiusAddition() const { return mCircleRadiusAddition; }
 
+    /**
+     * Sets a factor for increasing the label distances from the symbol.
+     * \param factor addition factor
+     * \see labelDistanceFactor()
+     */
+    void setLabelDistanceFactor( double factor ) { mLabelDistanceFactor = factor; }
+
+    /**
+     * Returns the factor for label distance from the symbol.
+     * \see setLabelDistanceFactor()
+     */
+    double labelDistanceFactor() const { return mLabelDistanceFactor; }
+
     /**
      * Returns the placement method used for dispersing the points.
      * \see setPlacement()
@@ -152,12 +165,14 @@ class CORE_EXPORT QgsPointDisplacementRenderer: public QgsPointDistanceRenderer
     QColor mCircleColor;
     //! Addition to the default circle radius
     double mCircleRadiusAddition = 0;
+    //! Factor for label distance
+    double mLabelDistanceFactor = 0.5;
 
     void drawGroup( QPointF centerPoint, QgsRenderContext &context, const QgsPointDistanceRenderer::ClusteredGroup &group ) override SIP_FORCE;
 
     //helper functions
     void calculateSymbolAndLabelPositions( QgsSymbolRenderContext &symbolContext, QPointF centerPoint, int nPosition, double symbolDiagonal, QList<QPointF> &symbolPositions, QList<QPointF> &labelShifts, double &circleRadius,
-                                           double &gridRadius, int &gridSize ) const;
+                                           double &gridRadius, int &gridSize, QList<double> &diagonals ) const;
     void drawCircle( double radiusPainterUnits, QgsSymbolRenderContext &context, QPointF centerPoint, int nSymbols );
     void drawSymbols( const ClusteredGroup &group, QgsRenderContext &context, const QList<QPointF> &symbolPositions );
     void drawGrid( int gridSizeUnits, QgsSymbolRenderContext &context,
diff --git a/src/gui/symbology/qgspointdisplacementrendererwidget.cpp b/src/gui/symbology/qgspointdisplacementrendererwidget.cpp
@@ -58,6 +58,7 @@ QgsPointDisplacementRendererWidget::QgsPointDisplacementRendererWidget( QgsVecto
   connect( mDistanceUnitWidget, &QgsUnitSelectionWidget::changed, this, &QgsPointDisplacementRendererWidget::mDistanceUnitWidget_changed );
   connect( mLabelColorButton, &QgsColorButton::colorChanged, this, &QgsPointDisplacementRendererWidget::mLabelColorButton_colorChanged );
   connect( mCircleModificationSpinBox, static_cast < void ( QDoubleSpinBox::* )( double ) > ( &QDoubleSpinBox::valueChanged ), this, &QgsPointDisplacementRendererWidget::mCircleModificationSpinBox_valueChanged );
+  connect( mLabelDistanceFactorSpinBox, static_cast < void ( QDoubleSpinBox::* )( double ) > ( &QDoubleSpinBox::valueChanged ), this, &QgsPointDisplacementRendererWidget::mLabelDistanceFactorSpinBox_valueChanged );
   connect( mScaleDependentLabelsCheckBox, &QCheckBox::stateChanged, this, &QgsPointDisplacementRendererWidget::mScaleDependentLabelsCheckBox_stateChanged );
   connect( mRendererSettingsButton, &QPushButton::clicked, this, &QgsPointDisplacementRendererWidget::mRendererSettingsButton_clicked );
   this->layout()->setContentsMargins( 0, 0, 0, 0 );
@@ -130,6 +131,8 @@ QgsPointDisplacementRendererWidget::QgsPointDisplacementRendererWidget( QgsVecto
   mLabelFontButton->setCurrentFont( mRenderer->labelFont() );
   mCircleModificationSpinBox->setClearValue( 0.0 );
   mCircleModificationSpinBox->setValue( mRenderer->circleRadiusAddition() );
+  mLabelDistanceFactorSpinBox->setClearValue( 0.5 );
+  mLabelDistanceFactorSpinBox->setValue( mRenderer->labelDistanceFactor() );
   mDistanceSpinBox->setValue( mRenderer->tolerance() );
   mDistanceUnitWidget->setUnit( mRenderer->toleranceUnit() );
   mDistanceUnitWidget->setMapUnitScale( mRenderer->toleranceMapUnitScale() );
@@ -336,6 +339,17 @@ void QgsPointDisplacementRendererWidget::mCircleModificationSpinBox_valueChanged
   emit widgetChanged();
 }
 
+void QgsPointDisplacementRendererWidget::mLabelDistanceFactorSpinBox_valueChanged( double d )
+{
+  if ( !mRenderer )
+  {
+    return;
+  }
+
+  mRenderer->setLabelDistanceFactor( d );
+  emit widgetChanged();
+}
+
 void QgsPointDisplacementRendererWidget::mDistanceSpinBox_valueChanged( double d )
 {
   if ( mRenderer )
@@ -388,6 +402,7 @@ void QgsPointDisplacementRendererWidget::blockAllSignals( bool block )
   mRendererComboBox->blockSignals( block );
   mLabelColorButton->blockSignals( block );
   mCircleModificationSpinBox->blockSignals( block );
+  mLabelDistanceFactorSpinBox->blockSignals( block );
   mScaleDependentLabelsCheckBox->blockSignals( block );
   mMinLabelScaleWidget->blockSignals( block );
   mCenterSymbolToolButton->blockSignals( block );
diff --git a/src/gui/symbology/qgspointdisplacementrendererwidget.h b/src/gui/symbology/qgspointdisplacementrendererwidget.h
@@ -60,6 +60,7 @@ class GUI_EXPORT QgsPointDisplacementRendererWidget: public QgsRendererWidget, p
     void mDistanceUnitWidget_changed();
     void mLabelColorButton_colorChanged( const QColor &newColor );
     void mCircleModificationSpinBox_valueChanged( double d );
+    void mLabelDistanceFactorSpinBox_valueChanged( double d );
     void mScaleDependentLabelsCheckBox_stateChanged( int state );
     void minLabelScaleChanged( double scale );
     void mRendererSettingsButton_clicked();
diff --git a/src/ui/qgspointdisplacementrendererwidgetbase.ui b/src/ui/qgspointdisplacementrendererwidgetbase.ui
diff --git a/tests/src/python/test_qgspointdisplacementrenderer.py b/tests/src/python/test_qgspointdisplacementrenderer.py
